TSPI vs VTTSX: 39% overlap
TSP I Fund — shown via international proxy and Vanguard Target Retirement 2060 share 38.9% of their portfolios by weight — computed as Σ min(wA, wB) over every holding both funds own.
Different holding dates. These holdings were published about 3 months apart — VTTSX as of 2026-03-31, the rest through 2026-06-30. Each fund is compared using its most recent file, so any trading in between shows up as a difference.
You would hold two tickers and get the diversification of 1.6. Two funds that shared nothing would score 2.0; two identical funds score 1.0.
Top shared holdings
TSPI and VTTSX hold 8,453 of the same securities. The ten contributing most to the overlap figure:
| Holding | in TSPI | in VTTSX | Δ |
|---|---|---|---|
| CASH | 2.4% | 2.0% | 0.5% |
| 2330 | 4.3% | 1.6% | 2.7% |
| 005930 | 2.3% | 0.8% | 1.4% |
| 000660 | 2.2% | 0.8% | 1.4% |
| ASML | 1.7% | 0.6% | 1.1% |
| 700 | 0.8% | 0.3% | 0.5% |
| HSBA | 0.7% | 0.3% | 0.5% |
| ROP | 0.6% | 0.3% | 0.4% |
| SAN | 0.7% | 0.2% | 0.4% |
| NOVN | 0.6% | 0.2% | 0.4% |
Where TSPI and VTTSX differ
Sector weights as a share of each fund, ordered by the size of the gap rather than the size of the sector — two funds that overlap heavily still usually diverge somewhere.
| Sector | TSPI | VTTSX | Δ |
|---|---|---|---|
| Financials | 19.7% | 14.1% | +5.5pp |
| Information Technology | 20.9% | 26.3% | −5.4pp |
| Treasuries | 0.0% | 3.3% | −3.3pp |
| Industrials | 13.8% | 10.6% | +3.2pp |
| Unclassified | 9.1% | 6.1% | +3.0pp |
| Communication Services | 3.3% | 6.0% | −2.7pp |
| Materials | 5.2% | 3.0% | +2.2pp |
| Health Care | 5.3% | 7.0% | −1.7pp |
Δ is TSPI minus VTTSX, in percentage points. Sector data is not published by every issuer, so “Unclassified” is a real category rather than a gap in the table.
What each fund holds alone
0.0% of TSPI by weight, held in no part of VTTSX.
59.1% of VTTSX by weight, held in no part of TSPI.
A large count with a small weight is the usual shape: the positions one fund adds are typically its smallest ones.
Concentration and cost
| TSPI | VTTSX | |
|---|---|---|
| Top 10 holdings | 16.3% | 19.3% |
| Positions held | 8,453 | 6 |
| Cost per $10,000 held, per year | $5 | $8 |
Cost is the expense ratio applied to $10,000; it excludes any brokerage commission, bid-ask spread or tax consequence. Figures are facts about the funds, not a suggestion about which to hold.
Frequently asked
How much do TSPI and VTTSX overlap?
TSPI and VTTSX overlap 38.9% by portfolio weight — moderate overlap. They share 8,453 holdings. The figure comes from current issuer holdings files (TSPI as of 2026-06-30, VTTSX as of 2026-03-31).
How is the overlap between TSPI and VTTSX calculated?
As the sum of the smaller weight in each fund, over every holding both funds own: Σ min(wA, wB). If TSPI holds a stock at 6% and VTTSX holds the same stock at 4%, 4% counts as shared. The result is bounded between 0% and 100%, and it is computed after looking through any fund-of-funds to the underlying holdings.
Is it redundant to hold both TSPI and VTTSX?
That depends on your goals — we state facts, not advice. At 38.9% overlap, each fund still contributes meaningfully distinct exposure.
What does TSPI own that VTTSX doesn't?
TSPI holds 8,453 positions and VTTSX holds 6; 0 of TSPI's positions don't appear in VTTSX at all, and they are 0.0% of TSPI by weight.
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Related comparisons
Sources: issuer holdings files, TSPI as of 2026-06-30, VTTSX as of 2026-03-31. Weights are fractions of each fund. Diagnostics, not advice.